Remove support for POST.

[GoodClover]

Line 38 of server.js
You are allowing the POST method to be used when this is deprecated in the coffee protocol.
Quote https://tools.ietf.org/html/rfc2324:

A coffee pot server MUST accept both the BREW and POST method
equivalently. However, the use of POST for causing actions to happen
is deprecated.

You should probably give a warning saying this is deprecated if used.

[GoodClover]

Also thought I'd mention in package.json your requiring express when that doesn't seem to be used.

[cybertelx]

A coffee pot server MUST accept both the BREW and POST method
equivalently. However, the use of POST for causing actions to happen
is deprecated.
They must accept both, so your main point is invalid
EDIT: Yeah they should probably make a warning